The second ionization energy, IE2 of the elements of the third row of the Period
ID: 817832 • Letter: T
Question
The second ionization energy, IE2 of the elements of the third row of the Periodic Table are given below.
Na- 4560 kJ/mol
Mg- 1445 kJ/mol
Al- 1815 kJ/mol
Si-1575 kJ/mol
P-1890 kJ/mol
S- 2260 kJ/mol
Cl- 2296 kJ/mol
Ar- 2665 kJ/mol
Plot the data and explain each of the following obsevrations:
(a) The IE2 for Na is much higher than for all of the other elements of this row
(b) The general trend from Mg to Ar is of increasing IE2
(c) The IE2 of Si is less than that of P
(d) The IE2 of Cl is very similar to that of S
Explanation / Answer
a) As Na looses one electron it attains noble gas configuration so its IE 2 is higher.
b) As IE increases along a period , So IE 2 also increases along a period as the size of atom decreases.
c) The size of phosporus decreases and one extra proton adds to it as the number of protons increase so there is an additional attracting force which leads to higher IE 2 than Silicon
d) As sulphur looses one electron it attains completely half filled orbitals as a result of which its IE 2 value is close to Cl